A variety of systems have been developed to provide for automatic steering of vehicles. Primarily, these systems have been designed for use in the factory or office environment. For example, robot courier and waste management vehicles may be automatically steered by embedding conductive material in the floor along the path on which the vehicle is to travel. These systems are extremely expensive and very difficult to modify due to the physical placement of electric conductors in subflooring of a building. The use of optical tracking systems has not been widely explored. However, similar automatically-steered vehicles have been developed that can track a stripe of material placed on the ceiling above the vehicle. These systems are not suitable for use in a highway environment due to the placement of the stripe above the vehicle. Further, there has been little attention to the problems associated with many vehicles utilizing the pathway to be tracked. Accordingly, need has arisen for an automatic vehicle steering system which is suitable for the highway environment and which addresses the problems associated with many vehicles using the automatic pathway.